Variable reactance transformer



ec. 3, 1942. J, TYRNERv 2,304,668

` VARIABLE REACTANGE TRANSFORMER Fmed Aug. 15, 1940 4 sheets-snaai 1.

D;., 1942.v UYRNER 2,304,668

VARIABLE REACTANCE IRANSFORMER` Filed Aug. l5, 1940 4 Sheets-Sheet 2 D698, 1942. y .1. TYRNr-:R l2,304,668

VARIABLE REACTANCE TRANSFQRMER DCC. 8, 1942. J, TYRNER 2,304,6@8

VARIABLE REACTANCE TRANSFORMER Filed Aug. l5, 1940 4 ShQeS-Sheet-ll "u W ,f5 37 1.9 .g o r j ab -C 2 IZ J4 3&5 36

INVENTOR. /W

t: 1n d l wram/Q) ,GTM/MEMS Patented Dec. 8, 1942 VARIABLE REACTANCE TRANSFOBMER Joseph Tyrner, Englewood, N. I., assignor to Air Reduction Company, Incorporated, New York. N. Y., a corporation of New York Application Augusty 15, 1940, Serial No. 352,680

Claims.

The present invention relates to transformers of the type employing movable windings for varying their reactance.

An important object of the invention is flexibility of construction in such transformers enabling them to be readily manufactured to meet the requirements of different ampere ranges. Other objects of the invention are simplicity of construction and low cost of manufacture. It is an aim of the invention that its foregoing objects be accomplished by a transformer construction aiording a wide range of reactance variation. A more specific object of the invention is to minimize the vibration or chattering inherent in the adjustment of the movable windings.

In accordance with the invention, a transformer construction is provided which comprises a pair of magnet members in form of rings disposed in axial alignment withl one another, and

-; two groups of magnet columns extending parallel to one another between the magnet rings. The two magnet column groups are disposed to successively alternate with one another circularly about the axis of the magnet rings. One of the two magnet column groups is embraced by two groups of transformer windings, one of which is made movable with respect to the other to vary the distance between the two transformer winding groups. This effects the desired reactance variation, a wide range of which is provided by the close spacing permitted between the two magnet column groups.

The foregoing transformer construction has the advantage of being readily adapted to different ampere ranges, by varying the size of the two magnet rings, which permits any desired number of magnet columns to be included in each of the two magnet column groups and consequently any desired number of transformer windings to be included in each of the two transformer winding groups.

The two magnet rings are carried by cylindrical supports'of standard size, the mean diameter of the magnet rings being varied to suit the conditions desired. Each of these rings may conveniently be formed of a convolved band of magnetic material, which permits their outer diameter to be readily varied.

Each of the various magnet columns may comprise two rectangular legs set at an angle to one another to form the letter V in cross-section. When made in this manner, the various magnet columns are positioned so that the angle between the two legs of any magnet column diverges away from the axis of the magnet rings. By proper choice of the angular setting of the two legs 'in each of the various magnet columns, a parallel spacing of the adjacent legs of any two adjacent magnet columns may be obtained. The total number of legs in said magnet columns is a multiple of four.

The two legs forming any of the various magnet columns may be made up of rectangular laminations of uniform size and provided with means common to both for securing them to one another and conjointly clamping together their respective laminations, a unitary structure being formed merely requiring a variation in the angle between the two legs to adapt it to the particular conditions desired.

The adjustment of the movable windings may be effected by the use of a threaded shaft journalled in the aforementioned supports for the magnet rings. Two nut-members may be provided on the threaded shaft in spaced relation to one another. The movable windings may be carried by a spider loosely surrounding the other by yieldable means operating with opposing forces on the supporting rods. Vibration or chattering in the adjustment of the movable windings is in" this manner effectively minimized.

The invention will be understood from the following description taken in conjunction with the accompanying drawings in which Fig. 1 is a view in side elevation of an embodiment of the invention; Fig. 2 is a vertical section on the line 21R- 2x of Fig. l, as seen from the right of that figure; and Figs. 3 and 4 are horizontal sections on the lines 3*-31 and lx--l of Fig. l, as seen from the top and bottom of that figure. respectively. 1

Referring particularly to Figs. 1 and 2, upper and lower cylindrical castings Il serve as the supports for upper and lower magnet rings i2: Each of the supporting castings Il is provided with an inwardly projecting annular flange Ila;

and each of the magnet rings I2 is constructedv by winding a band of magnetic material on the flange Ha of its respective supporting casting Il. This construction of the two'magnet' rings I2 is facilitated by upper and lower annular guide plates Il rigidly secured to the two supporting castings il around their annular flanges Il a, as by welding. The two magnet rings I2 contact with these guide plates, the outer diameter of which is purposely made large to permit varying 6.1.1 Liza the outer diameter oi the two magnet rings l2. The two bands oi magnetic material forming the two magnet rings l2 may be prevented from uncoiling by welding their outer ends to the convolutions underneath. Suitable base members l5 are secured by welding or otherwise to the lower plate lll. Centrally mounted for rotation in the upper and lower castings Il is a threaded shaft provided with an upper operating handvfneel l'l.

The embodiment of the invention shown in the drawings comprises a total of six magnet columns it, which are disposed at regular intervals about the axis of the shaft i6 .and Contact at their ends with the two magnet rings l2. As best shown in Figs. 3 and 4, each of the six magnet columns iii comprises two rectangular legs disposed at an angle to one another to form the letter V in erom-section, and is positioned so that the angle between the two legs 20 diverges away from the axis of the shalt i6. The angle between the two legs 2li is the same for each of the sixlmagnet columns i9, and is such that the adjacent legs 20 oi any two adjacent magnet columns I9 are parallelly spaced with respect to each other.

Each of the two legs 2U forming any of the sb: magnet columns i9 may be made up of rectangular laminations of the same size extending cross-wise to the longest cross-sectional leg dimension. as shown in Figs. 3 and 4, and held between inner and outer vertical angle members El and 22, respectively. Each of the six magnet columns l@ thus includes in its construction an er pair of clamping members 2l and an outer pair of clamping members 22` The inner two members 2l may be rigidly connected to one another by welding them to a number of vertically rod members willie the outer two mernbers 22 may be rigidly connected to one another welding them to a number of Saddlehaped members 25. Bolts 26 passing through the saddleshaped members 2.5 serve to draw the two pairs o! rigidly connected clamping members 2l and 22 toward one anot er. Each of the six magnet columns l@ thus constitutes a unitary structure capable of independent assembly. As shown in Fig. 2, the upper and lower rod members 24 included in magnet column construction have nut-carrying threaded ends 22a which extend through holes in the magnet rings i2, the plates i4 and the upper and lower casting it; whereby each of the sh: magnet columns l is held in place between the magnet rings i2, which are held against their adjacent plates lll secured to the upper and lower castings il.

rShe embodiment of the invention shown in the drawings comprises a total of sin transformer windings consisting of three iixed windings 21 sind three movable windings As will be noted, the windings are arranged in pairs alternately embracing three of the magnet columns li each pair consisting o e, fixed winding 2l and a mov c winding The fixed windings are preily made larger than the movable windings to permit movement oi the latter into and out cf the TF lformer. l'lach o the six windings is substany triangularshaped with the view to minimizing the spacing between any two adjacent mag-- net columns As shown, the three ilxed windings 2l are positloned around the uppermost portions of their embraced magnet colurnns lili The means to Supn port them in this position includes upper and lower clamping plates 29 and Sil between which they are firmly held at their inner portions by bolts 3l passing through bosses 32 formed on the upper casting l l and abutting the upper plates 28, and at their outer portions on bars 34 supported on tie-rods 35 hanging from the upper plate N.

The three movable windings 2li are supported on a spider 36 loosely surrounding the shaft i6. The shape of this spider is shown in Fig. 4. It comprises a central port-ion 36a from which extend three pairs of complementary arms 36h and 36C. Each of the three movable windings 28 is partly carried by a pair of these arms 38h and 36o, to which it is secured by straps 3l, while another strap 39 secures it to the central spider portion 36a.

Referring particularly to Fig. 2, the spider 36 is connected to the shaft I6 through a resilient mounting comprising three bolts 40 rigidly secured to the spider 36 at their lower ends. Spaced apart and threaded on the shaft I6 are two nutmembers 4l provided with appropriate openings through which the bolts 40 pass freely so as to permit sliding movement, compression springs 42 being provided on the bolts 40 above the nutmernbers 4l and compression 4springs 44 being provided below the nut-members 4|. The upper springs 42 exert upward forces on the bolts 40 and downward forces on the upper nut-member Il; while the lower springs t4 exert downward forces on the spider 36 and upward forces on the lower nutrnember 4l. This resilient mounting is thus effective in taking up any tendency of loose play between the nut-members 4l while at rest or in motion on the shaft I6, thereby insuring that the spider 36 may be operated in either direction of adjustment substantially without chattering or vibration. Preferably, the upper springs compensate for the iorces of repulsion exerted on,

the movable windings 28 by the iixed windings 21;

As shown in Fig. 4, rotational displacement of the spider 36 by the rotation of the shaft I6 is pre-f' vented by a strip of non-conducting material secured at its ends to two of the complementary spider arms 36h and 3BG and adapted to freely ride on a fixed rod 4S mounted in the upper and lower plates M.

In transformers of the type to which the present invention relates, the primaries are made of smaller wire than the secondaries. Therefore, in the embodiment of the invention shown in the drawings, it is preferred to use the movable windings 28 as the primaries and the xed windings 2'! es the secondarles. However, this is not essential, since it is possible to use the fixed windings 2l as the primaries and the movable windings 28 as the secondarles. Concerning the transformer flux established by the cornM bined action of the various windings, it is apparent that it is made to travel in opposite dia rections through any two adjacent magnet columns le.

From the foregoing description, lt is clear that the movable windings 28 may be moved by the shaft i6 between the extreme positions in which they respectively surround the uppermost and iowerrnost portions of their embraced magnet columns i9. in their uppermost position, the movable windings 28 are completely disposed within the xed windings 2l, because of which the leakage iiux is very low. By reason of the close spacing of the various magnet columns i9, the leakage flux nevertheless increases at a rapid rate as thernovable windings 28 are moved out of the xed windings 2l and attains a maximum of considerable value at the lowermost position of the movable windings 28. It is apparent that the embodiment of the invention shown in the drawings provides for an exceptionally wide range of reactance variation Because of the large forces prevailing in transformers of the type to which the present `invention relates, it has in general been foundimpracticable because of chattering hitherto to construct them for heavy current duty. In accordance with the invention, however, transformers of well over 400 ampere maximum current capacity may be obtained without difficulty.

The embodiment of the invention shown in the drawings may have its various windings conf nected in various ways depending on the use to n which the transformer is applied. It may thus be used as a. single phase transformer by parallel connection of its movable windings 28 (serving as primaries) to the source, and by parallel iconnection of its ilxed windings 21 (serving as secondaries) to the load. As a 3phase transformer, of course, its movable 4windings 2B (serving as primaries) may be Y or A connect-ed to the source, while its fixed windings 21 (serving as secondaries) may be Y or A connected to the load.

It is to be understood that the invention is` not limited to the particular embodiment shown in the drawings. which embodiment may be modified in various ways without departing from the spirit of the invention,

What is claimed is:

1. A transformer comprising a pair of magnet rings disposed in axial alignment with one another, a first group of magnet columns extending parallel to one another between said ymagnet rings, two groups of windings embracing said tnrst group of magnet columns, a second group .of magnet columns extending parallel to one .another between said magnet rings, said two imagnet ,column groups being disposed to successively alternate with one another about the axis of said magnet rings, each of the columns included in said two magnet column groups consisting of two rectangular legs set at an angle to one another to form the letter V in cross-section and being positioned to cause said angle to diverge away from the axis of said magnet rings, and means for varying the distance between said two winding groups. Q

2. A transformer comprising a pair of magnet rings disposed in axial alignment with one another, a first group of magnet columns extending parallel to one another between said magnet rings, two groups of windings embracing said ilrst group of magnet columns, a second group of magnet columns extending parallel to one another between said magnet rings, said two magnet column groups being disposed to successively alternate with one another about the axis of said magnet rings, each of the columns included in said two magnet column groups consisting of two rectangular legs set at an angle to one another to form the letter V in cross-section and being positioned to cause said angle to diverge away from the axis of said magnet rings, said angle being chosen to cause the adjacent legs of any two adjacent magnet columns to be spaced parallel from one another, and means for varying the distance between said two winding groups.

3. In a transformer construction, the combination with a movable winding of a means for moving said winding comprising a threaded shaft, two nut-members disposed on said shaftl in spaced relation to one another. a plurality of bolts supporting said winding and movably extending through openings in said nut-members, and yieldable means operating with opposing forces on said bolts and urging said nutmembers toward one another.

4. In a transformer construction, the combination with movable windings of a means for moving said windings comprising a threaded shaft, two nut-members disposed on said shaft in spaced relation to one another, a supporting spider for said windings loosely surrounding said shaft, a plurality of bolts connected to said spider and movably extending through openings in said nutmembers, and yieldable means operating with opposing forces on said bolts and urging said nut-members toward one another.

5. In a transformer construction, the combination with a ilrst winding and a second winding of a means for moving said first winding toward andaway from said second winding, said means comprising a threaded shaft, two nut-members disposed on said shaft in spaced relation to one another, a plurality of bolts supporting said iirst winding and movably extending through openings in said nut-members, and yieldable means operating with opposing forces on said bolts and urging said nut-members toward one another, said yieldable means operating on said bolts with a less force in the direction of motion of said iirst winding toward said second winding than in the direction of motion of said ilrst winding away from said second winding.

6. A transformer comprising two magnet rings spaced apart and ydisposed in axial alignment with one another, magnet columns having pairs of legs to a total number which is a multiple of four all of which are secured in a circular arrangement between and abutting said magnet rings, pairs oi' windings surrounding alternate pairs of legs of said magnet columns, and means for simultaneously varying the distance between the windings of each pair of windings.

7. A transformer comprising a pair of magnet rings disposed in axial alignment with one another, magnet columns having pairs of legs to a total number which is a multiple of four all of which are secured in a circular-arrangement between and abutting said magnet rings, pairs of windings surrounding alternate pairs of legs of said magnet columns, a winding of each pair being capable oi' nesting within the other winding of that pair, and means for simultaneously varying the distance between the windings of each pair of windings.

8. A transformer comprising a pair of magnet rings disposed in axial alignment with one another, a plurality of magnet columns all secured in a circular arrangement about the axis of Said magnet rings and parallel to one another between said magnet rings, a group of windings embracing alternate magnet columns, another group of windings embracing the same alternate magnet columns, and means for varying the distance between said two groups of windings.

9. A transformer comprising a pair of magnet rings disposed in axial alignment with one another, a plurality of magnet columns all secured in a circular arrangement about the axis of said magnet rings and parallel to one another between said magnet rings, the said magnet rings and magnet columns being each laminated so that all of the laminations of both the magnet rings and the magnet columns lie in substantially cylindrical planes about said axis, a group of windings embracing alternate magnet columns, another group of windings embracing the same alternate magnet columns, and means for varying the distance between said two groups of windings. 10. A transformer comprising a. pair of magnet rings disposed in axial alignment with one another and each formed of a convolved band o! magnetic material, a. plurality of magnet co1- umns each longitudinally laminated so that all of its laminations are substantiallyperallel to the laminations of said magnet rings, all o! said magnet columns being secured in a circular arrangement about the axis of said magnet rings and parallel to one another between said magnet rings, a group of windings embracing alternate magnet columns, another group oi' windings embracing the same alternate magnet columns, and means for varying the distance between the two groups of windings.

JOSEPH TYRNER. 

